I found it, I had checked the "Justify Paragraphs" option. It behaves strangely though. This is clearly not a VE issue anymore, but I don't know were it belongs, do you?

On a related note, is it possible to get uncompressed CSS? I just have this huge pile in a style element which dosen't tell me where it's from.

I havn't added any custom CSS/JS, but I do use the "Vector" theme, is that the cause?

See before and after screenshots above.

Hm, kinda right, but then there is the issue of the justified text which doesn't seam to be related to ↵.

In the editor it is shown as a ↵ character, and I assume it is a hard line break, which I changed into a regular line break. The next edit uses two line breaks, which fixes the formatting issue. However in VE it doesn't justify the text. I've attached some screenshots to make it clearer.